iOS 11 only works with 64 bit apps

I just read the the latest iOS version, 11, will only work with 64 bit apps. How do I know if my apps meet this requirement? Is it a function of a setting in nsbasic, the windows operating system, the windows computer processor characteristics, or what? At this time I do not want to update my iPhone to iOS 11 until I am sure that my apps will work.

Thank you!

Dick

We’ve been running iOS 11 on our devices here for a couple of months. Everything is fine.

WebApps run using Safari, which is 64 bit (of course).

PhoneGap Apps built after 2015 will also be 64 bit.